126 Dr. Bennett on Parasitic Vegetable Structures. 



species of Gonimn, more particularly Goniwn hyaliniim, glaucum, and 

 tranquiUum. The genus Gonium, as at present constituted, lie thinks 

 consists both of animal and vegetable species. 



The following are the generic characters of Sarcina : — " Plants 

 coriaceous, transparent, consisting of sixteen, or sixty-four four- 

 celled square frustules, arranged parallel to one another in a square 

 transparent matrix." 



The species under consideration is denominated by Mr. Goodsir 

 Sarcina ventricuU, and is thus defined : " Frustules sixteen ; colour 

 light brown ; transparent matrix very perceptible between the frus- 

 tules, less so around the edges ; size 800 to 1000 of an inch. 



Hab. The human stomach." 



A perfect individual Sarcina consists then " of sixty-four ultimate 

 cells, but as soon as each of these again divides into, or produces 

 four new cells, the individual becomes composite, and may forthwith 

 divide into four young ones, each of these again to undergo the same 

 quaternar)^ division." The parts of the individuals are arranged in 

 the square ; these parts increase in numbers in a geometrical pro- 

 gression, and the species propagates according to the same law, four 

 in the first generation, sixteen in the second, sixty-four in the third, 

 256 in the fourth, 1024 in the fifth, and so on with a rapidity pe- 

 culiar to such a series of numbers. The liquid of the stomach in 

 which the Sarcina was found, was analysed by Dr. George Wilson, 

 Lecturer on Chemistry in Edinburgh ; he found three acids in it, — 

 hydrochloric, acetic, and lactic. The first was present in very small 

 quantity, while the two others (more especially the acetic) Avere 

 abundant. 



Since the publication of Mr. Goodsir's paper, similar organisms 

 have been detected in other cases of stomach complaint by Dr. J. H. 

 Davidson and Mr. Benjamin Joseph Bell, of Edinburgh. ' 



XXIV. — On the Parasitic Vegetable Structures found growing 

 in Living Animals. By J. H. Bennett, M.D.* 



The objects of this memoir, as stated by the author, are — " 1st, 

 to confirm and extend the observations and experiments of Gruby 

 concerning the mycodermatous vegetations found in the crusts of the 

 disease called Tinea favosa, or Porrigo lupinosa of Bateman ; 2nd, 

 to announce the occasional existence, and describe a plant found 

 growing on the lining membrane or cheesy matter of tubercular ca- 

 vities in the lungs of man ; 3rd, to describe the structure of a plant 

 found growing on the skin of the gold-fish ; and 4th, from a review 

 of all the facts hitherto recorded in connexion with this subject, to 

 draw certain conclusions respecting the j^fithological state which 

 furnishes the conditions necessary for the growth of fungi in living 

 animals." 



* In the Transactions of the Royal Society of Edinburgh, vol. xv. 



